The component of a vector `r` along X-axis will have maximum value if

Options

A. r is along positive Y-axis
B. r is along positive X-axis
C. r makes an angle of `45^(@)` with the X-axis
D. r is along negative Y-axis

Answer

B

Explanation

Let r makes an angle `theta` with positive x-axis component of r along X-axis
`r_(x)=|r| cos theta`
`(r_(x))_("maximum")=|r| (cos theta)_("maximum")`
`=|r| cos 0^(@)=|r| " "` (`:. Costheta ` is maximum of `theta=0^(@)`)
As `" " theta=0^(@)`,
r is along positive x-axis.